A semiconductor light emitting device includes a substrate, a processing layer which is formed on the substrate and is processed in nano size, an n type semiconductor layer which is formed on the substrate to cover the processing layer, an active layer which is formed on the n type semiconductor layer, and a p type semiconductor layer which is formed on the active layer.
There is also a face-up type semiconductor light emitting device which includes a sapphire substrate having a front surface corresponding to a light emission surface and an opposite rear surface, and an n-GaN layer, a light emitting layer, a p-GaN layer and a transparent electrode, which are formed in order on the front surface of the sapphire substrate. In this semiconductor light emitting device, a p electrode is formed on the transparent electrode and an n electrode is formed on the n-GaN layer exposed by removing a portion of the p-GaN layer and the light emitting layer. In addition, a reflective layer, a barrier layer and an AuSn layer are formed in order on the rear surface of the sapphire substrate.